Description: drm/amd/display: Fix 'panel_cntl' could be null in 'dcn21_set_backlight_level()'
References:
Notes:
 carnil> Introduced in 474ac4a875ca ("drm/amd/display: Implement some asic specific abm
 carnil> call backs."). Vulnerable versions: 5.9-rc1.
Bugs:
upstream: released (6.8-rc4) [e96fddb32931d007db12b1fce9b5e8e4c080401b]
6.7-upstream-stable: released (6.7.5) [0c863cab0e9173f8b6c7bc328bee3b8625f131b5]
6.6-upstream-stable: released (6.6.17) [2e150ccea13129eb048679114808eb9770443e4d]
6.1-upstream-stable: needed
5.10-upstream-stable: needed
4.19-upstream-stable: N/A "Vulnerable code not present"
sid: released (6.7.7-1)
6.1-bookworm-security: needed
5.10-bullseye-security: needed
4.19-buster-security: N/A "Vulnerable code not present"